Signaling for uplink sounding

ABSTRACT

Computing readable media, apparatuses, and methods for signaling for uplink sounding are disclosed. An apparatus is disclosed comprising processing circuitry. The processing circuitry may be configured to: decode a trigger frame comprising a resource unit (RU) allocation, and a spatial stream (SS) allocation for the first wireless device to transmit an uplink (UL) sounding signal, where the trigger frame include an indication that the trigger frame is for the UL sounding signal. The processing circuitry may be further configured to: determine a path loss based on the indication of the transmit power and a received power of the trigger frame at the first wireless device. The processing circuitry may be configured to: determine a transmit power for the UL sounding signal based on the path loss, and transmit the UL sounding signal in accordance with the RU allocation, the SS allocation, and the transmit power.

PRIORITY CLAIM

This application claims the benefit of priority under 35 USC 119(e) toU.S. Provisional Patent Application Ser. No. 62/303,415, filed Mar. 4,2016, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments pertain to wireless networks and wireless communications.Some embodiments relate to wireless local area networks (WLANs) andWi-Fi networks including networks operating in accordance with the IEEE802.11 family of standards. Some embodiments relate to IEEE 802.11ax.Some embodiments relate to signaling for uplink sounding. Someembodiments relate to methods, computer readable media, and apparatusfor signaling for uplink (UL) sounding.

BACKGROUND

Efficient use of the resources of a wireless local-area network (WLAN)is important to provide bandwidth and acceptable response times to theusers of the WLAN. However, often there are many devices trying to sharethe same resources and some devices may be limited by the communicationprotocol they use or by their hardware bandwidth. Moreover, wirelessdevices may need to operate with both newer protocols and with legacydevice protocols.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which likereferences indicate similar elements and in which:

FIG. 1 illustrates a WLAN in accordance with some embodiments;

FIG. 2 illustrates a method for signaling for uplink sounding inaccordance with some embodiments;

FIG. 3 illustrates a trigger frame for uplink sounding in accordancewith some embodiments;

FIG. 4 illustrates a common information field of a trigger frame inaccordance with some embodiments;

FIG. 5 illustrates per user information for a trigger frame inaccordance with some embodiments;

FIG. 6 illustrates an example of received signal strength by the masterstation in accordance with some embodiments;

FIG. 7 illustrates an example of received signal strength by the masterstation in accordance with some embodiments;

FIG. 8 illustrates a method for signaling for uplink sounding inaccordance with some embodiments;

FIG. 9 illustrates a method for signaling for uplink sounding inaccordance with some embodiments;

FIG. 10 illustrates a method for signaling for uplink sounding inaccordance with some embodiments; and

FIG. 11 illustrates a block diagram of an example machine upon which anyone or more of the techniques (e.g., methodologies) discussed herein mayperform.

DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1 illustrates a WLAN 100 in accordance with some embodiments. TheWLAN 100 may comprise a basis service set (BSS) 100 that may include amaster station 102, which may be an AP, a plurality of high-efficiencywireless (e.g., IEEE 802.11ax) (HE) stations 104, and a plurality oflegacy (e.g., IEEE 802.11n/ac) devices 106.

The master station 102 may be an AP using the IEEE 802.11 to transmitand receive. The master station 102 may be a base station. The masterstation 102 may use other communications protocols as well as the IEEE802.11 protocol. The IEEE 802.11 protocol may be IEEE 802.11ax. The IEEE802.11 protocol may include using orthogonal frequency divisionmultiple-access (OFDMA), time division multiple access (TDMA), and/orcode division multiple access (CDMA). The IEEE 802.11 protocol mayinclude a multiple access technique. For example, the IEEE 802.11protocol may include space-division multiple access (SDMA) and/ormultiple-user multiple-input multiple-output (MU-MIMO). There may bemore than one master station 102 that is part of an extended service set(ESS). A controller (not illustrated) may store information that iscommon to the more than one master stations 102.

The legacy devices 106 may operate in accordance with one or more ofIEEE 802.11 a/b/g/n/ac/ad/af/ah/aj/ay, or another legacy wirelesscommunication standard. The legacy devices 106 may be STAs or IEEE STAs.The HE STAs 104 may be wireless transmit and receive devices such ascellular telephone, portable electronic wireless communication devices,smart telephone, handheld wireless device, wireless glasses, wirelesswatch, wireless personal device, tablet, or another device that may betransmitting and receiving using the IEEE 802.11 protocol such as IEEE802.11ax or another wireless protocol. In some embodiments, the HE STAs104 may be termed high efficiency (HE) stations.

The master station 102 may communicate with legacy devices 106 inaccordance with legacy IEEE 802.11 communication techniques. In exampleembodiments, the master station 102 may also be configured tocommunicate with HE STAs 104 in accordance with legacy IEEE 802.11communication techniques.

In some embodiments, a HE frame may be configurable to have the samebandwidth as a channel. The HE frame may be a physical Layer ConvergenceProcedure (PLCP) Protocol Data Unit (PPDU).

The bandwidth of a channel may be 20 MHz, 40 MHz, or 80 MHz, 160 MHz,320 MHz contiguous bandwidths or an 80+80 MHz (160 MHz) non-contiguousbandwidth. In some embodiments, the bandwidth of a channel may be 1 MHz,1.25 MHz, 2.03 MHz, 2.5 MHz, 4.06 MHz, 5 MHz and 10 MHz, or acombination thereof or another bandwidth that is less or equal to theavailable bandwidth may also be used. In some embodiments the bandwidthof the channels may be based on a number of active data subcarriers. Insome embodiments the bandwidth of the channels is based on 26, 52, 106,242, 484, 996, or 2×996 active data subcarriers or tones that are spacedby 20 MHz. In some embodiments the bandwidth of the channels is 256tones spaced by 20 MHz. In some embodiments the channels are multiple of26 tones or a multiple of 20 MHz. In some embodiments a 20 MHz channelmay comprise 242 active data subcarriers or tones, which may determinethe size of a Fast Fourier Transform (FFT). An allocation of a bandwidthor a number of tones or sub-carriers may be termed a resource unit (RU)allocation in accordance with some embodiments.

In some embodiments, The 26-subcarrier RU and 52-subcarrier RU are usedin the 20 MHz, 40 MHz, 80 MHz, 160 MHz and 80+80 MHz OFDMA HE PPDUformats. The 106-subcarrier RU is used in the 20 MHz, 40 MHz, 80 MHz,160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats. The242-subcarrier RU is used in the 40 MHz, 80 MHz, 160 MHz and 80+80 MHzOFDMA and MU-MIMO HE PPDU formats. The 484-subcarrier RU is used in the80 MHz, 160 MHz and 80+80 MHz OFDMA and MU-MIMO HE PPDU formats. The996-subcarrier RU is used in the 160 MHz and 80+80 MHz OFDMA and MU-MIMOHE PPDU formats.

A HE frame may be configured for transmitting a number of spatialstreams, which may be in accordance with MU-MIMO and may be inaccordance with OFDMA. In other embodiments, the master station 102, HESTA 104, and/or legacy device 106 may also implement differenttechnologies such as code division multiple access (CDMA) 2000, CDMA2000 1×, CDMA 2000 Evolution-Data Optimized (EV-DO), Interim Standard2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856(IS-856), Long Term Evolution (LTE), Global System for Mobilecommunications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSMEDGE (GERAN), IEEE 802.16 (i.e., Worldwide Interoperability forMicrowave Access (WiMAX)), BlueTooth®, or other technologies.

Some embodiments relate to HE communications. In accordance with someIEEE 802.11 embodiments, e.g, IEEE 802.11ax embodiments, a masterstation 102 may operate as a master station which may be arranged tocontend for a wireless medium (e.g., during a contention period) toreceive exclusive control of the medium for an HE control period. Insome embodiments, the HE control period may be termed a transmissionopportunity (TXOP). The master station 102 may transmit a HE master-synctransmission, which may be a trigger frame or HE control and scheduletransmission, at the beginning of the HE control period. The masterstation 102 may transmit a time duration of the TXOP and sub-channelinformation. During the HE control period, HE STAs 104 may communicatewith the master station 102 in accordance with a non-contention basedmultiple access technique such as OFDMA or MU-MIMO. This is unlikeconventional WLAN communications in which devices communicate inaccordance with a contention-based communication technique, rather thana multiple access technique. During the HE control period, the masterstation 102 may communicate with HE stations 104 using one or more HEframes. During the HE control period, the HE STAs 104 may operate on asub-channel smaller than the operating range of the master station 102.During the HE control period, legacy stations refrain fromcommunicating. The legacy stations may need to receive the communicationfrom the master station 102 to defer from communicating.

In accordance with some embodiments, during the TXOP the HE STAs 104 maycontend for the wireless medium with the legacy devices 106 beingexcluded from contending for the wireless medium during the master-synctransmission. In some embodiments the trigger frame may indicate anuplink (UL) UL-MU-MIMO and/or UL OFDMA TXOP. In some embodiments, thetrigger frame may include a DL UL-MU-MIMO and/or DL OFDMA with aschedule indicated in a preamble portion of trigger frame.

In some embodiments, the multiple-access technique used during the HETXOP may be a scheduled OFDMA technique, although this is not arequirement. In some embodiments, the multiple access technique may be atime-division multiple access (TDMA) technique or a frequency divisionmultiple access (FDMA) technique. In some embodiments, the multipleaccess technique may be a space-division multiple access (SDMA)technique. In some embodiments, the multiple access technique may be aCode division multiple access (CDMA).

The master station 102 may also communicate with legacy stations 106and/or HE stations 104 in accordance with legacy IEEE 802.11communication techniques. In some embodiments, the master station 102may also be configurable to communicate with HE stations 104 outside theHE TXOP in accordance with legacy IEEE 802.11 communication techniques,although this is not a requirement.

In some embodiments the HE station 104 may be a “group owner” (GO) forpeer-to-peer modes of operation. A wireless device may be a HE station102 or a master station 102.

In some embodiments, the HE station 104 and/or master station 102 may beconfigured to operate in accordance with IEEE 802.11mc.

In example embodiments, the HE station 104 and/or the master station 102are configured to perform the methods and functions described herein inconjunction with FIGS. 1-11.

FIGS. 2-7 will be disclosed in conjunction with one another. FIG. 2illustrates a method 200 for signaling for uplink sounding in accordancewith some embodiments. Illustrated in FIG. 2 master station 102, HEstations 104, time 202 along a horizontal axis, frequency 204 along avertical axis, and operation 250 along the top. The frequency 204 may bea bandwidth of the wireless medium. The frequencies 204 may overlap. Forexample, HE station 104.1 and HE station 104.2 may transmit on the samefrequency using MU-MIMO. Additionally, one or more of the HE stations104 may transmit on the same frequency 204 or an overlapping frequency204 in responding to the master station 102. The master station 102 mayinclude an analog-to-data converter (ADC) 212.

The method 200 begins at operation 252 with the master station 102transmitting trigger frame 206.1. The master station 102 may havecontended for the wireless device prior to transmitting the triggerframe 206.1. The trigger frame 206.1 may be a trigger frame 300.

FIG. 3 illustrates a trigger frame 300 for uplink sounding in accordancewith some embodiments. Trigger frame 300 includes one or more of thefollowing fields common information 320 and per user information 340.The common information 320 includes fields that are common to all theusers addressed in the trigger frame 300. The per user information 340includes one or more fields that are particular for a user that isidentified.

FIG. 4 illustrates a common information 320 field of a trigger frame 400in accordance with some embodiments. FIG. 5 illustrates per userinformation 340 for a trigger frame 300 in accordance with someembodiments.

The common information 320 may include an access point (AP) transmit(TX) power 322, a carrier sense (CS) required 324, a cascade indicator326, an NDP type 328, a length or duration 330, and a trigger frame type332. The AC TX power 322 may indicate a transmission power used totransmit the trigger frame 400. The AC TX power 322 may indicate the TXpower as the power ratio in decibels (dB) of the measured powerreferenced to one milliwatt (mW)(dBm.) The CS required 324 indicateswhether the user is to perform a CS before transmitting a response. Thecascade indicator 326 indicates whether a subsequent trigger frame 300is to be transmitted. The NDP type 328 may indicate parameters forresponding. The NDP type 328 may indicate that a HE preamble symbolduration that should be used, e.g., 3.2 μs (1× long-training field(LTF)), 6.4 is (2×LTF), or 12.8 μs (4×LTF). The NDP type 328 mayindicate that a legacy NDP should be transmitted, e.g., an IEEE 802.11acNDP format, or an IEEE 802.11 In NDP format. In some embodiments, theNDP type 328 may be two fields one to indicate the symbol duration andanother to indicate the type of NDP to use. In addition, the NDP type328 may indicate the P-matrix size e.g. 1×1, 2×2, 4×4, 6×6, and 8×8. TheP-matrix is used for multiplexing the LTF symbols of multiple spatialstreams. The length or duration 330 may indicate a length or durationfor the response to the trigger frame. In some embodiments, the lengthor duration 330 may indicate the trigger frame is for an uplink soundingby indicating there is no length or duration 330 for data. The triggerframe type 332 may indicate a type of trigger frame which may includeuplink sounding.

The per user information 340 may include resource unit (RU) allocation342, spatial stream (SS) allocation 344, target received signal strengthindicator (RSSI) 346, association identification (AID) 348, and a delay350. The RU allocation 342 may be an indication of a bandwidth andlocation of the bandwidth. The SS allocation 344 may be an indication ofa SS allocation for the RU allocation 342. In some embodiments, the RUallocation 342 and SS allocation 344 fields may be merged.

The target RSSI 346 may be a target power for the user to transmit apacket to the transmitter of the trigger frame 300. In some embodiments,target RSSI 346 may be part of the common information 320. The AID 348may be an identification of the user that the user recognizes asidentifying the user. For example, the AID 348 may be an identificationthat was sent to the user when the user associated with the AP. Thedelay 350 may indicate when a user should transmit the sounding signal.For example, the delay 350 may indicate a duration to wait or a numberof other groups of users that are to transmit before the user.

The trigger frame 206.2 may include a cascade indicator 326 thatindicates there is a subsequent trigger frame to be transmitted, e.g.,trigger frame 206.2.

Returning to method 200, trigger frame 206.1 may include one or more ofthe fields disclosed in conjunction with FIG. 3, e.g. an RU allocation342 and SS allocation 344 for HE station 104.1 and HE station 104.2. Themethod 200 continues at operation 254 with HE station 104.1 and HEstation 104.2 waiting a period of time before transmitting. For example,HE station 104.1 and HE station 104.2 may wait a short interframe space(SIFS).

In some embodiments, the HE stations 104 perform a clear channelassessment (CCA) prior to transmitting the sounding signal 208. If theCCA indicates the wireless medium (e.g., the wireless medium indicatedby the RU 342) is idle, then the HE station 104 will transmit thesounding signal 208. If the CCA indicates the wireless medium is busy,then the HE station 104 may defer until the wireless medium indicatesidle or may not transmit the sounding signal 208.

The method 200 continues at operation 256 with the HE stations 104transmitting sounding signals 208. The sounding signals 208 include atransmit power (TXP) 209, which is the transmit power used to transmitthe sounding signal 208 and not a field of the sounding signal 208.

In some embodiments, the HE stations 104 may determine the TXP 209 to bethe TXP for the highest modulation and coding scheme (MCS) for an uplinkwith the master station 102. The HE stations 104 may determine an uplinkpath loss based on an AC TX power 322 and a received power of thetrigger frame 206. For example, the path loss may be the AC TX power 322minus the received power of the trigger frame 206. The AC TX power 322may be for a portion of the trigger frame 206, e.g., the payload ormedia access control (MAC) portion. The MCSs may have error vectormagnitude (EVM) requirements with higher MCSs permitting smaller EVMs.The HE stations 104 then transmit the sounding signal 208 with the TXP209 set to the TXP that the HE stations 104 would use to transmit apacket to the master station 102 using the highest MCS the HE station104 could use with the master station 102. In some embodiments, areliability parameter may be the EVM and indicate that thecommunications must stay within an EVM requirement for a predeterminedportion of the communication. In some embodiments, the highest MCS isthe one that achieves the highest data rate for the specific uplink. Forexample, the highest MCS the device can encode is MCS7 but the uplinkmay only support up to MCS5 due to path loss. The highest MCS for thisexample uplink is then MCS5 and not MCS7.

The HE station 104 may be constrained in how high the TXP 209 may bebased on regulatory standards (which may be based on the RU 342). The HEstation 104 may be constrained in how high the TXP 209 may be based onanother communication protocol being co-located with the HE station 104,e.g., BlueTooth™. The HE station 104 may be constrained in how high theTXP 209 may be based on physical limits of the HE station 104, e.g.maximum output power of the power amplifier. In this embodiment, themaster station 102 may be able to measure the highest usable powers forthe highest MCSs of the HE stations 104 based on the received power atthe master station 102.

The master station 102 may receive the sounding signal 208. FIG. 6illustrates an example 600 of received signal strength by the masterstation 102 in accordance with some embodiments. Illustrated in FIG. 6is HE station index 602 along a horizontal axis, and received power 604along a vertical axis. The embodiment where the HE stations 104determine the TXP 209 to be the TXP for the highest MCS for an uplinkwith the master station 102 may result in signal strengths 604 asillustrated in FIG. 6. ADC 212 of the master station 102 may havedifficulty determining the received power 604 for each of the HEstations 104 because of the large difference in received power 604. Thelarge difference in received power 604 may result from large differencein path loss from the master station 102 to HE stations 104. The powerdifference between the best and worst HE station 104 may cause underflowor overflow of the ADC 212 and the output of a Fast Fourier Transform(FFT) of the master station 102. For example, received power 604difference between HE station 104.2 and HE station 104.1 may be toogreat for the ADC 212.

In some embodiments, the HE stations 104 may determine the TXP 209 to bea highest power under regulation limits, co-location limits, andphysical limits. The master station 102 may receive the sounding signal208. In this embodiment, the power difference between the best and worstHE station 104 may cause underflow or overflow of the ADC 212 and theoutput of a FFT of the master station 102. For example, returning toFIG. 6, received power 604 difference between HE station 104.2 and HEstation 104.1 may be too great for the ADC 212.

In some embodiments, the master station 102 may specify a target for thereceived power of the sounding signal 208, e.g., target RSSI 346. Insome embodiments, the HE stations 104 determine the TXP 209 by assuminga path loss is reciprocal for downlink and uplink. The HE stations 104calculate the path loss based on the received power of the trigger frame206 and an AC TX power 322. The TXP 209 is then the minimum of the TXPfor highest MCS usable with the master station 102 and the targetreceived power plus the path loss determined from the trigger frame 206.The HE station 104 transmitting at a TXP 209 to have a same receivedpower at the master station 102 may result in the ADC 212 and FFT of themaster station 102 not overflowing.

The master station 102 may receive the sounding signal 208. FIG. 7illustrates an example 700 of received signal strength by the masterstation 102 in accordance with some embodiments. Illustrated in FIG. 7is HE station index 702 along a horizontal axis, received power 704along a vertical axis, a curve of highest received power 706, and atarget power 708. FIG. 7 may illustrate received power 704 for anembodiment where the HE stations 104 try to reach a target power 708,e.g., target RSSI 346. The master station 102 may need to set a lowreceived power 704 target so that each HE station 104 may come close tothe target power 708.

The master station 102 may not know what additional power is availableto each of the HE station 104 because of the low setting of the targetpower 708. For example, in FIG. 7, HE station 104.2 may be able totransmit at a higher power and potentially use a higher MCS. The masterstation 102 may perform a new sounding with the HE stations 104.2 thathad a received power 704 greater than the target power 708 with a highertarget power 708 to determine more information regarding availablepowers for the HE stations 104.2.

In some embodiments, the master station 102 may determine path losses ofthe HE stations 104 using the sounding signal 208.

Returning to method 200, the method 200 may continue with the masterstation 102 waiting a duration 258 before transmitting a second triggerframe 206.2. For example, the master station 102 may wait a SIFSduration. The second trigger frame 206.2 may include one or more of thefields disclosed in conjunction with FIG. 3, e.g. an RU allocation 342and SS allocation 344 for HE station 104.3 and HE station 104.4. Thesecond trigger frame 206.2 may include a cascade indicator 326 thatindicates there is not a subsequent trigger frame 206 is to betransmitted.

The method 200 continues at operation 262 with HE station 104.3 and HEstation 104.4 waiting a period of time before transmitting. For example,HE station 104.3 and HE station 104.4 may wait a SIFS. The method 200continues at operation 264 with HE station 104.3 and HE station 104.4transmitting sounding signal 208.3 and sounding signal 208.4,respectively, with TXP 209.3 and TXP 209.4, respectively. Operations260, 262, and 264 may be the same or similar as operations 252, 254, and256.

In some embodiments, the TXP 209 is a target receive power density andmay be part of a common field. In some embodiments, the TXP 209 isnormalized. For example, the RU allocation 342 may be 20 MHz and anominal bandwidth may be 80 MHz. The HE station 104 may reduce TXP 209proportionally for the 20 MHz bandwidth. In some embodiments, the TXP209 is a target receive power density and may be part of a common field.

In some embodiments, operations 258 and 260 are optional. The triggerframe 206.1 may include RU allocation 342 and SS allocation 344 for HEstation 104.1, HE station 104.2, HE station 104.3, and HE station 104.4.In these embodiments, the trigger frame 206.1 includes an indication ofwhen the HE stations 104 should transmit the sounding signals 208. Forexample, trigger frame 206.1 may include delay 350 that indicates thatHE station 104.3 and HE station 104.4 are to wait to transmit in asecond group of HE stations 104. HE station 104.3 and HE station 104.4may determine the time to wait based on a length or duration in thetrigger frame 206.1 and the time to wait in operations 254 and 262.

FIG. 8 illustrates a method 800 for signaling for uplink sounding inaccordance with some embodiments. The method 800 begins at operation 802with decoding a trigger frame comprising a RU allocation, and a SSallocation for the first wireless device to transmit an UL soundingsignal, and wherein the trigger frame comprises an indication that thetrigger frame is for the UL sounding signal and an indication of atransmit power used by a second wireless device to transmit the triggerframe.

For example, an apparatus of HE stations 104.1 and 104.2 may decodetrigger frame 206.1 which may include RU allocation 342, SS allocation344, trigger frame type 332, and AC TX power 322.

The method 800 continues at operation 904 with determining a path lossbased on the indication of the transmit power and a received power ofthe trigger frame at the first wireless device.

For example, an apparatus of HE station 104.1 may determine a path lossfrom the master station 102 to the HE station 104.1 based on an AC TXpower 322 of trigger frame 206.1 and a received power of the triggerframe 206.1 by the HE station 104.1.

The method 800 continues at operation 806 with determining a transmitpower for the UL sounding signal based on the path loss. For example,the trigger frame may further comprises a target RSSI 346 for thesounding signal, and an apparatus of HE station 104.1 may determine thetransmit power for the sounding signal based on the path loss so thatthe sounding signal will be received by the second wireless device withthe target receive power.

In another embodiment, an apparatus of the HE station 104.1 maydetermine the transmit power to be a power below a limit but largeenough for a highest MCS the first wireless device is able to use toencode a packet to transmit to the second wireless device. The limit maybe a regulatory transmission limit for the RU allocation or aco-location transmission limit. The apparatus may determine the highestMCS the first wireless device is able to use based on an estimated EVMof a packet encoded with the highest MCS to be received at the secondwireless device.

Optionally, the method 800 continues at operation 808 with waitingbefore transmitting the sounding signal. The trigger frame may include afield to indicate a delay time. For example, trigger frame 206.1 mayinclude delay 350. The delay 350 may indicate a time for the HE station104 to delay prior transmitting the sounding signal.

The method 800 continues at operation 810 with configure the firstwireless device to transmit the UL sounding signal in accordance withthe RU allocation, the SS allocation, and the transmit power. Forexample, an apparatus of HE station 104.1 may configure HE station 104.1to transmit the sounding signal in accordance with RU allocation 342, SSallocation 344, and the transmit power for the sounding signal that wasdetermined in a previous operation.

The sounding signal may be transmitted in accordance with one or both ofOFDMA or MU-MIMO. For example, if the RU allocation is 20 MHz and the SSallocation indicates two spatial streams then the HE station 104.1 maytransmit in accordance with both OFDMA and MU-MIMO. If the RU allocationindicates a full bandwidth (e.g., 160 MHz), and the SS allocationindicates two spatial streams then the HE station 104.1 may transmit inaccordance with MU-MIMO. If the RU allocation indicates 20 MHz and theSS allocation indicates just one spatial stream for the RU allocation,then the HE station 104.1 may transmit in accordance with OFDMA only.

FIG. 9 illustrates a method 900 for signaling for uplink sounding inaccordance with some embodiments. The method 900 begins at operation 902with decode a trigger frame comprising a RU allocation, and a SSallocation for the wireless device to transmit an UL sounding signal,and wherein the trigger frame comprises an indication that the triggerframe is for the UL sounding signal.

For example, an apparatus of HE station 104.1 may decode trigger frame206.1 which may include RU allocation 342, SS allocation 344, andtrigger frame type 332.

The method 900 may continue at operation 904 with determine a transmitpower to transmit the UL sounding signal based on a highest power thefirst wireless can use for the RU allocation.

For example, an apparatus of HE station 104.1 may determine a highestpower that HE station 104.1 may transmit a packet based on regulatorylimits for the RU allocation 342, and, optionally, based on co-locatedother wireless communication protocols, e.g. BlueTooth™.

Optionally, the method 900 continues at operation 906 with waitingbefore transmitting the sounding signal in accordance with a delay. Thetrigger frame may include a field to indicate a delay. For example,trigger frame 206.1 may include delay 350. The delay 350 may indicate atime for the HE station 104 to delay prior transmitting the soundingsignal, e.g. a group number.

For example, HE station 104.3 may receive a delay 350 that indicates itis in a second group of HE stations 104.3 to transmit the soundingsignal. HE station 104.3 can determine how long to wait based on thetimes to wait operations 254 and 262 and a length or duration of thesounding signal 208. The delay 350 may indicate how long the HE station104 is to wait in other ways.

The method 900 continues at operation 908 with configure the wirelessdevice to transmit the UL sounding signal in accordance with the RUallocation, the SS allocation, and the transmit power.

For example, an apparatus of HE station 104.1 may configure HE station104.1 to transmit the sounding signal 208.1 with TXP 209.1 in accordancewith the determined transmit power and in accordance with RU allocationand SS allocation.

FIG. 10 illustrates a method 1000 for signaling for uplink sounding inaccordance with some embodiments. The method 1000 begins at operation1002 with encoding the additional trigger frame comprising second RUallocations, and second spatial stream (SS) allocations for a pluralityof third wireless devices to transmit a second plurality of UL soundingsignals, and comprising a second indication that the additional triggerframe is for the second plurality of UL sounding signals.

For example, master station 102 may encode trigger frame 206.1 toinclude RU allocations, SS allocations 344, AIDs 348 (of the pluralityof second wireless devices), and trigger frame type 332 (or length orduration 330 when the trigger frame type is indicated by a length orduration that indicates the trigger frame is for UL sounding. In someembodiments, the trigger frame may include one or more of an AC TX power322, a CS 324, a cascade indicator 326, an NDP type 328, a target RSSI346, or a delay 350.

The method 1000 may continue at operation 1004 with configuring thefirst wireless device to transmit the additional trigger frame to theplurality of third wireless devices. For example, an apparatus of themaster station 102 may configure the master station 102 to transmit thetrigger frame 206.1 to the HE stations 104.1, 104.2, 104.3, and 104.4.

The method 1000 may continue at operation 1006 with decoding the secondplurality of UL sounding signals from the plurality of third wirelessdevices.

For example, an apparatus of the master station 102 may decode soundingsignals 208 from HE station 104.1 and HE station 104.2.

In some embodiments, the apparatus of the master station 102 isconfigured to indicate a delay for each of the plurality of secondwireless devices to transmit the UL sounding signals, where the delay isa same first delay for a first one or more of the plurality of secondwireless devices and a same second delay for a second one or more of theplurality of second wireless devices.

For example, master station 102 may indicate a first delay (delay 350)for HE station 104.1 and HE station 104.2 and a second delay (delay 350)for HE stations 104.3 and HE stations 104.4.

In some embodiments, the trigger frame comprises a cascade field thatindicates an additional trigger is to be transmitted. For example, anapparatus of master station 102 may indicate that cascade indicator 326is true for trigger frame 206.1 and that cascade indicator 326 is falsefor trigger frame 206.2.

In some embodiments, the master station 102 may be configured to selecta second plurality of second wireless devices of the plurality of secondwireless devices with a receive signal strength of the sounding signalabove a threshold for an additional trigger frame, and encode anadditional trigger frame comprising second RU allocations, and second SSallocations for the second plurality of second wireless devices totransmit a second plurality of UL sounding signals. For example, masterstation 102 may receive sounding signals 208 as disclosed in conjunctionwith FIG. 7. The master station 102 may select HE stations 104.1 through104.4 because the received power of these sounding signals 208 is higherthan the target power 708. The master station 102 may then transmit anadditional trigger frame to HE stations 104.1 through 104.4 with ahigher target power 708 to determine the head room or the additionalpower that HE stations 104.1 through 104.4 can use to transmit to themaster station 102. The master station 102 may repeat this method with ahigher target power 708.

FIG. 11 illustrates a block diagram of an example machine 1100 uponwhich any one or more of the techniques (e.g., methodologies) discussedherein may perform. In alternative embodiments, the machine 1100 mayoperate as a standalone device or may be connected (e.g., networked) toother machines. In a networked deployment, the machine 1100 may operatein the capacity of a server machine, a client machine, or both inserver-client network environments. In an example, the machine 1100 mayact as a peer machine in peer-to-peer (P2P) (or other distributed)network environment. The machine 1100 may be a master station 102, HEstation 104, personal computer (PC), a tablet PC, a set-top box (STB), apersonal digital assistant (PDA), a mobile telephone, a smart phone, aweb appliance, a network router, switch or bridge, or any machinecapable of executing instructions (sequential or otherwise) that specifyactions to be taken by that machine. Further, while only a singlemachine is illustrated, the term “machine” shall also be taken toinclude any collection of machines that individually or jointly executea set (or multiple sets) of instructions to perform any one or more ofthe methodologies discussed herein, such as cloud computing, software asa service (SaaS), other computer cluster configurations.

Examples, as described herein, may include, or may operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a machine readable medium. In an example, thesoftware, when executed by the underlying hardware of the module, causesthe hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using software, the general-purpose hardware processor may beconfigured as respective different modules at different times. Softwaremay accordingly configure a hardware processor, for example, toconstitute a particular module at one instance of time and to constitutea different module at a different instance of time.

Machine (e.g., computer system) 1100 may include a hardware processor1102 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 1104 and a static memory 1106, some or all of which maycommunicate with each other via an interlink (e.g., bus) 1108. Themachine 1100 may further include a display device 1110, an input device1112 (e.g., a keyboard), and a user interface (UI) navigation device1114 (e.g., a mouse). In an example, the display device 1110, inputdevice 1112 and UI navigation device 1114 may be a touch screen display.The machine 1100 may additionally include a mass storage (e.g., driveunit) 1116, a signal generation device 1118 (e.g., a speaker), a networkinterface device 1120, and one or more sensors 1121, such as a globalpositioning system (GPS) sensor, compass, accelerometer, or othersensor. The machine 1100 may include an output controller 1128, such asa serial (e.g., universal serial bus (USB), parallel, or other wired orwireless (e.g., infrared (IR), near field communication (NFC), etc.)connection to communicate or control one or more peripheral devices(e.g., a printer, card reader, etc.). In some embodiments the processor1102 and/or instructions 1124 may comprise processing circuitry and/ortransceiver circuitry.

The storage device 1116 may include a machine readable medium 1122 onwhich is stored one or more sets of data structures or instructions 1124(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 1124 may alsoreside, completely or at least partially, within the main memory 1104,within static memory 1106, or within the hardware processor 1102 duringexecution thereof by the machine 1100. In an example, one or anycombination of the hardware processor 1102, the main memory 1104, thestatic memory 1106, or the storage device 1116 may constitute machinereadable media.

While the machine readable medium 1122 is illustrated as a singlemedium, the term “machine readable medium” may include a single mediumor multiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 1124.

An apparatus of the machine 1100 may be one or more of a hardwareprocessor 1102 (e.g., a central processing unit (CPU), a graphicsprocessing unit (GPU), a hardware processor core, or any combinationthereof), a main memory 1104 and a static memory 1106, some or all ofwhich may communicate with each other via an interlink (e.g., bus) 1108.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 1100 and that cause the machine 1100 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withsuch instructions. Non-limiting machine readable medium examples mayinclude solid-state memories, and optical and magnetic media. Specificexamples of machine readable media may include: non-volatile memory,such as semiconductor memory devices (e.g., Electrically ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM)) and flash memory devices; magnetic disks, such asinternal hard disks and removable disks; magneto-optical disks; RandomAccess Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples,machine readable media may include non-transitory machine readablemedia. In some examples, machine readable media may include machinereadable media that is not a transitory propagating signal.

The instructions 1124 may further be transmitted or received over acommunications network 1126 using a transmission medium via the networkinterface device 1120 utilizing any one of a number of transferprotocols (e.g., frame relay, internet protocol (IP), transmissioncontrol protocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as Wi-Fi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards, a LongTerm Evolution (LTE) family of standards, a Universal MobileTelecommunications System (UMTS) family of standards, peer-to-peer (P2P)networks, among others.

In an example, the network interface device 1120 may include one or morephysical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or moreantennas to connect to the communications network 1126. In an example,the network interface device 1120 may include one or more antennas 1160to wirelessly communicate using at least one of single-inputmultiple-output (SIMO), multiple-input multiple-output (MIMO), ormultiple-input single-output (MISO) techniques. In some examples, thenetwork interface device 1120 may wirelessly communicate using MultipleUser MIMO techniques. The term “transmission medium” shall be taken toinclude any intangible medium that is capable of storing, encoding orcarrying instructions for execution by the machine 1100, and includesdigital or analog communications signals or other intangible medium tofacilitate communication of such software.

Various embodiments may be implemented fully or partially in softwareand/or firmware. This software and/or firmware may take the form ofinstructions contained in or on a non-transitory computer-readablestorage medium. Those instructions may then be read and executed by oneor more processors to enable performance of the operations describedherein. The instructions may be in any suitable form, such as but notlimited to source code, compiled code, interpreted code, executablecode, static code, dynamic code, and the like. Such a computer-readablemedium may include any tangible non-transitory medium for storinginformation in a form readable by one or more computers, such as but notlimited to read only memory (ROM); random access memory (RAM); magneticdisk storage media; optical storage media; flash memory, etc.

The following examples pertain to further embodiments. Example 1 is anapparatus of a first wireless device, the apparatus including: memory;and processing circuitry coupled to the memory, the processing circuitryconfigured to: decode a trigger frame including a resource unit (RU)allocation, and a spatial stream (SS) allocation for the first wirelessdevice to transmit an uplink (UL) sounding signal, and wherein thetrigger frame comprises an indication that the trigger frame is for theUL sounding signal and an indication of a transmit power used by asecond wireless device to transmit the trigger frame; determine a pathloss based on the indication of the transmit power and a received powerof the trigger frame at the first wireless device; determine a transmitpower for the UL sounding signal based on the path loss; and configurethe first wireless device to transmit the UL sounding signal inaccordance with the RU allocation, the SS allocation, and the transmitpower.

In Example 2, the subject matter of Example 1 optionally includeswherein the trigger frame further comprises a target receive power forthe UL sounding signal, and wherein the processing circuitry is furtherconfigured to: determine the transmit power for transmission of the ULsounding signal based on the path loss so that the UL sounding signalwill be received by the second wireless device with the target receivepower.

In Example 3, the subject matter of Example 2 optionally includeswherein processing circuitry is further configured to: normalize thetarget receive power in accordance with a bandwidth of the RUallocation, wherein the target receive power is a target receive powerdensity.

In Example 4, the subject matter of any one or more of Examples 1-3optionally include wherein the processing circuitry is furtherconfigured to: determine the transmit power to be a power below a limitbut large enough for a highest modulation and coding scheme (MCS) thefirst wireless device is able to use to encode a packet to transmit tocommunicate with the second wireless device within a reliabilityparameter.

In Example 5, the subject matter of Example 4 optionally includeswherein the limit is a regulatory transmission limit for the RUallocation, a co-location transmission limit, or a power amplifierlimit.

In Example 6, the subject matter of any one or more of Examples 4-5optionally include wherein the processing circuitry is furtherconfigured to: determine the highest MCS the first wireless device isable to use based on an estimated error vector magnitude (EVM) of apacket to be received at the second wireless device, wherein the packetis to be encoded with the highest MCS.

In Example 7, the subject matter of any one or more of Examples 1-6optionally include wherein the trigger frame comprises a carrier sensefield to indicate if the first wireless device is to perform a clearchannel analysis (CCA) before transmitting the UL sounding signal, andwherein the processing circuitry is configured to: if the carrier sensefield indicates that a CCA is to be performed before transmitting the ULsounding signal, perform a clear channel analysis (CCA) on the RUallocation, and if the CCA indicates the RU allocation is idle,configure the first wireless device to transmit the UL sounding signalin accordance with the RU allocation, the SS allocation, and thetransmit power.

In Example 8, the subject matter of any one or more of Examples 1-7optionally include wherein the UL sounding signal is a null data packet(NDP).

In Example 9, the subject matter of any one or more of Examples 1-8optionally include wherein the trigger frame indicates that the triggerframe is for the UL sounding signal based on a length or duration fieldof the trigger frame that indicates there is no length or duration fordata, or based on a trigger frame type field.

In Example 10, the subject matter of any one or more of Examples 1-9optionally include wherein the trigger frame indicates the UL soundingsignal is to be one from the following group: an high efficiency (HE)preamble symbol duration of 3.2 μs (1× long-training field (LTF)), a HEpreamble symbol duration of 6.4 μs (2×LTF), a HE preamble symbolduration of 12.8 μs (4×LTF), a legacy NDP, an Institute of Electricaland Electronic Engineers (IEEE) 802.11ac NDP format, or an IEEE 802.11nNDP.

In Example 11, the subject matter of any one or more of Examples 1-10optionally include wherein the trigger frame further comprises a delaytime that indicates how long the first wireless device is to wait beforetransmitting the UL sounding signal in accordance with the RU allocationand the SS allocation.

In Example 12, the subject matter of Example 11 optionally includeswherein one or more additional wireless devices are to transmit ULsounding signals before the delay time.

In Example 13, the subject matter of any one or more of Examples 1-12optionally include wherein the processing circuitry is furtherconfigured to: determine a transmit power to transmit the UL soundingsignal based on the path loss and further based on a bandwidth of the RUallocation.

In Example 14, the subject matter of any one or more of Examples 1-13optionally include wherein the trigger frame indicates that noacknowledgment of the UL sounding signal is to be transmitted by thesecond wireless device.

In Example 15, the subject matter of any one or more of Examples 1-14optionally include wherein the processing circuitry is furtherconfigured to: configure the first wireless device to transmit the ULsounding signal in accordance with the RU allocation, the SS allocation,and the transmit power, and in accordance with one or both of orthogonalfrequency division multi-access (OFDMA) or multi-user multiple-inputmulti-output (MU-MIMO).

In Example 16, the subject matter of any one or more of Examples 1-15optionally include wherein the first wireless device is one from thefollowing group: an Institute of Electrical and Electronic Engineers(IEEE) 802.11ax access point, an IEEE 802.11ax station, an IEEE 802.11station, and an IEEE 802.11 access point.

In Example 17, the subject matter of any one or more of Examples 1-16optionally include transceiver circuitry coupled to the processingcircuitry.

In Example 18, the subject matter of Example 17 optionally includes oneor more antennas coupled to the transceiver circuitry.

Example 19 is a non-transitory computer-readable storage medium thatstores instructions for execution by one or more processors, theinstructions to configure the one or more processors to cause anapparatus of a first wireless device to: decode a trigger frameincluding a resource unit (RU) allocation, and a spatial stream (SS)allocation for the first wireless device to transmit an uplink (UL)sounding signal, and wherein the trigger frame comprises an indicationthat the trigger frame is for the UL sounding signal and an indicationof a transmit power used by a second wireless device to transmit thetrigger frame; determine a path loss based on the indication of thetransmit power and a received power of the trigger frame at the firstwireless device; determine a transmit power for the UL sounding signalbased on the path loss; and configure the first wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power.

In Example 20, the subject matter of Example 19 optionally includeswherein the instructions further configure the one or more processors tocause the apparatus to: determine the transmit power for transmission ofthe UL sounding signal based on the path loss so that the UL soundingsignal will be received by the second wireless device with a targetreceive power, wherein the trigger frame further comprises the targetreceive power for the UL sounding signal.

Example 21 is a method performed by a first wireless device, the methodincluding: decode a trigger frame including a resource unit (RU)allocation, and a spatial stream (SS) allocation for the first wirelessdevice to transmit an uplink (UL) sounding signal, and wherein thetrigger frame comprises an indication that the trigger frame is for theUL sounding signal and an indication of a transmit power used by asecond wireless device to transmit the trigger frame; determine a pathloss based on the indication of the transmit power and a received powerof the trigger frame at the first wireless device; determine a transmitpower for the UL sounding signal based on the path loss; and configurethe first wireless device to transmit the UL sounding signal inaccordance with the RU allocation, the SS allocation, and the transmitpower.

In Example 22, the subject matter of Example 21 optionally includeswherein the trigger frame further comprises a target receive power forthe UL sounding signal, and wherein the method further comprises:determining the transmit power for transmission of the UL soundingsignal based on the path loss so that the UL sounding signal will bereceived by the second wireless device with the target receive power.

Example 23 is an apparatus of a wireless device, the apparatusincluding: memory; and processing circuitry coupled to the memory, theprocessing circuitry configured to: decode a trigger frame including aresource unit (RU) allocation, and a spatial stream (SS) allocation forthe wireless device to transmit an uplink (UL) sounding signal, andwherein the trigger frame comprises an indication that the trigger frameis for the UL sounding signal; determine a transmit power to transmitthe UL sounding signal based on a highest power the first wireless canuse for the RU allocation; and configure the wireless device to transmitthe UL sounding signal in accordance with the RU allocation, the SSallocation, and the transmit power.

In Example 24, the subject matter of Example 23 optionally includeswherein the highest power is based on one of the following group: aregulatory highest power for the RU allocation and a co-located wirelesscommunication protocol highest power.

Example 25 is an apparatus of a first wireless device, the apparatusincluding: memory; and processing circuitry coupled to the memory, theprocessing circuitry configured to: encode a trigger frame includingresource unit (RU) allocations, and spatial stream (SS) allocations fora plurality of second wireless devices to transmit a plurality of uplink(UL) sounding signals, and including an indication that the triggerframe is for the plurality of UL sounding signals; configure the firstwireless device to transmit the trigger frame to the plurality of secondwireless devices; and decode the plurality of UL sounding signals fromthe plurality of second wireless devices.

In Example 26, the subject matter of Example 25 optionally includeswherein the trigger frame further comprises an indication of a delay foreach of the plurality of second wireless devices to transmit the ULsounding signals, and wherein the delay is a same first delay for afirst one or more of the plurality of second wireless devices and a samesecond delay for a second one or more of the plurality of secondwireless devices.

In Example 27, the subject matter of any one or more of Examples 25-26optionally include wherein the trigger frame comprises a cascade fieldthat indicates an additional trigger frame is to be transmitted andwherein the processing circuitry is further configured to: encode theadditional trigger frame including second RU allocations, and secondspatial stream (SS) allocations for a plurality of third wirelessdevices to transmit a second plurality of UL sounding signals, andincluding a second indication that the additional trigger frame is forthe second plurality of UL sounding signals; configure the firstwireless device to transmit the additional trigger frame to theplurality of third wireless devices; and decode the second plurality ofUL sounding signals from the plurality of third wireless devices.

In Example 28, the subject matter of any one or more of Examples 25-27optionally include wherein the trigger frame further comprises a targetreceive power for the plurality of UL sounding signals.

In Example 29, the subject matter of Example 28 optionally includeswherein the processing circuitry is further configured to: select asecond plurality of second wireless devices of the plurality of secondwireless devices with a receive signal strength of the plurality of ULsounding signals above a threshold for an additional trigger frame;encode the additional trigger frame including second RU allocations, andsecond SS allocations for the second plurality of second wirelessdevices to transmit a second plurality of UL sounding signals, andincluding an indication that the additional trigger frame is for thesecond plurality of UL sounding signals, and wherein the additionaltrigger frame comprises a second target receive power greater than thetarget receive power; configure the first wireless device to transmitthe additional trigger frame to the second plurality of second wirelessdevices; and decode the second plurality of UL sounding signals from theplurality of second wireless devices.

Example 30 is an apparatus of a first wireless device, the apparatusincluding: means for decoding a trigger frame including a resource unit(RU) allocation, and a spatial stream (SS) allocation for the firstwireless device to transmit an uplink (UL) sounding signal, and whereinthe trigger frame comprises an indication that the trigger frame is forthe UL sounding signal and an indication of a transmit power used by asecond wireless device to transmit the trigger frame; means fordetermining a path loss based on the indication of the transmit powerand a received power of the trigger frame at the first wireless device,means for determining a transmit power for the UL sounding signal basedon the path loss; and means for configuring the first wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power.

In Example 31, the subject matter of Example 30 optionally includeswherein the trigger frame further comprises a target receive power forthe UL sounding signal, and wherein the apparatus further comprises:means for determining the transmit power for transmission of the ULsounding signal based on the path loss so that the UL sounding signalwill be received by the second wireless device with the target receivepower.

In Example 32, the subject matter of Example 31 optionally includes theapparatus further including: means for normalizing the target receivepower in accordance with a bandwidth of the RU allocation, wherein thetarget receive power is a target receive power density.

In Example 33, the subject matter of any one or more of Examples 30-32optionally include the apparatus including: means for determining thetransmit power to be a power below a limit but large enough for ahighest modulation and coding scheme (MCS) the first wireless device isable to use to encode a packet to transmit to communicate with thesecond wireless device within a reliability parameter.

In Example 34, the subject matter of Example 33 optionally includeswherein the limit is a regulatory transmission limit for the RUallocation, a co-location transmission limit, or a power amplifierlimit.

In Example 35, the subject matter of Example 34 optionally includes theapparatus further including: means for determining the highest MCS thefirst wireless device is able to use based on an estimated error vectormagnitude (EVM) of a packet to be received at the second wirelessdevice, wherein the packet is to be encoded with the highest MCS.

In Example 36, the subject matter of any one or more of Examples 30-35optionally include wherein the trigger frame comprises a carrier sensefield to indicate if the first wireless device is to perform a clearchannel analysis (CCA) before transmitting the UL sounding signal, andwherein the apparatus further comprises: if the carrier sense fieldindicates that a CCA is to be performed before transmitting the ULsounding signal, means for performing a clear channel analysis (CCA) onthe RU allocation, and if the CCA indicates the RU allocation is idle,means for configuring the first wireless device to transmit the ULsounding signal in accordance with the RU allocation, the SS allocation,and the transmit power.

In Example 37, the subject matter of any one or more of Examples 30-36optionally include wherein the UL sounding signal is a null data packet(NDP).

In Example 38, the subject matter of any one or more of Examples 30-37optionally include wherein the trigger frame indicates that the triggerframe is for the UL sounding signal based on a length or duration fieldof the trigger frame that indicates there is no length or duration fordata, or based on a trigger frame type field.

In Example 39, the subject matter of any one or more of Examples 30-38optionally include wherein the trigger frame indicates the UL soundingsignal is to be one from the following group: an high efficiency (HE)preamble symbol duration of 3.2 μs (1× long-training field (LTF)), a HEpreamble symbol duration of 6.4 μs (2×LTF), a HE preamble symbolduration of 12.8 μs (4×LTF), a legacy NDP, an Institute of Electricaland Electronic Engineers (IEEE) 802.11ac NDP format, or an IEEE 802.11nNDP.

In Example 40, the subject matter of any one or more of Examples 30-39optionally include wherein the trigger frame further comprises a delaytime that indicates how long the first wireless device is to wait beforetransmitting the UL sounding signal in accordance with the RU allocationand the SS allocation.

In Example 41, the subject matter of Example 40 optionally includeswherein one or more additional wireless devices are to transmit ULsounding signals before the delay time.

In Example 42, the subject matter of any one or more of Examples 30-41optionally include wherein the apparatus further comprises: means fordetermining a transmit power to transmit the UL sounding signal based onthe path loss and further based on a bandwidth of the RU allocation.

In Example 43, the subject matter of any one or more of Examples 30-42optionally include wherein the trigger frame indicates that noacknowledgment of the UL sounding signal is to be transmitted by thesecond wireless device.

In Example 44, the subject matter of any one or more of Examples 30-43optionally include the apparatus further including: means forconfiguring the first wireless device to transmit the UL sounding signalin accordance with the RU allocation, the SS allocation, and thetransmit power, and in accordance with one or both of orthogonalfrequency division multi-access (OFDMA) or multi-user multiple-inputmulti-output (MU-MIMO).

In Example 45, the subject matter of any one or more of Examples 30-44optionally include wherein the first wireless device is one from thefollowing group: an Institute of Electrical and Electronic Engineers(IEEE) 802.11ax access point, an IEEE 802.11ax station, an IEEE 802.11station, and an IEEE 802.11 access point.

In Example 46, the subject matter of any one or more of Examples 30-45optionally include means for processing radio signals.

In Example 47, the subject matter of Example 46 optionally includesmeans for transmitting and receiving radio signals.

Example 48 is a non-transitory computer-readable storage medium thatstores instructions for execution by one or more processors, theinstructions to configure the one or more processors to cause anapparatus of a first wireless device to: decode a trigger frameincluding a resource unit (RU) allocation, and a spatial stream (SS)allocation for the wireless device to transmit an uplink (UL) soundingsignal, and where the trigger frame comprises an indication that thetrigger frame is for the UL sounding signal; determine a transmit powerto transmit the UL sounding signal based on a highest power the firstwireless can use for the RU allocation; and configure the wirelessdevice to transmit the UL sounding signal in accordance with the RUallocation, the SS allocation, and the transmit power.

In Example 49, the subject matter of Example 48 optionally includeswhere the highest power is based on one of the following group: aregulatory highest power for the RU allocation and a co-located wirelesscommunication protocol highest power.

Example 50 is a method performed by an apparatus of a first wirelessdevice, the method including: decoding a trigger frame including aresource unit (RU) allocation, and a spatial stream (SS) allocation forthe wireless device to transmit an uplink (UL) sounding signal, andwhere the trigger frame comprises an indication that the trigger frameis for the UL sounding signal; determining a transmit power to transmitthe UL sounding signal based on a highest power the first wireless canuse for the RU allocation; and configuring the wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power.

In Example 51, the subject matter of Example 50 optionally includeswhere the highest power is based on one of the following group: aregulatory highest power for the RU allocation and a co-located wirelesscommunication protocol highest power.

Example 52 is an apparatus of a first wireless device, the apparatusincluding: means for decoding a trigger frame including a resource unit(RU) allocation, and a spatial stream (SS) allocation for the wirelessdevice to transmit an uplink (UL) sounding signal, and where the triggerframe comprises an indication that the trigger frame is for the ULsounding signal; means for determining a transmit power to transmit theUL sounding signal based on a highest power the first wireless can usefor the RU allocation; and means for configuring the wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power.

In Example 53, the subject matter of Example 52 optionally includeswhere the highest power is based on one of the following group: aregulatory highest power for the RU allocation and a co-located wirelesscommunication protocol highest power.

Example 54 is a non-transitory computer-readable storage medium thatstores instructions for execution by one or more processors, theinstructions to configure the one or more processors to cause anapparatus of a first wireless device to: encode a trigger frameincluding resource unit (RU) allocations, and spatial stream (SS)allocations for a plurality of second wireless devices to transmit aplurality of uplink (UL) sounding signals, and including an indicationthat the trigger frame is for the plurality of UL sounding signals;configure the first wireless device to transmit the trigger frame to theplurality of second wireless devices; and decode the plurality of ULsounding signals from the plurality of second wireless devices.

In Example 55, the subject matter of Example 54 optionally includeswhere the trigger frame further comprises an indication of a delay foreach of the plurality of second wireless devices to transmit the ULsounding signals, and where the delay is a same first delay for a firstone or more of the plurality of second wireless devices and a samesecond delay for a second one or more of the plurality of secondwireless devices.

In Example 56, the subject matter of any one or more of Examples 54-55optionally include where the trigger frame comprises a cascade fieldthat indicates an additional trigger frame is to be transmitted andwhere the instructions further configure the one or more processors tocause the apparatus to: encode the additional trigger frame includingsecond RU allocations, and second spatial stream (SS) allocations for aplurality of third wireless devices to transmit a second plurality of ULsounding signals, and including a second indication that the additionaltrigger frame is for the second plurality of UL sounding signals;configure the first wireless device to transmit the additional triggerframe to the plurality of third wireless devices; and decode the secondplurality of UL sounding signals from the plurality of third wirelessdevices.

In Example 57, the subject matter of any one or more of Examples 54-56optionally include where the trigger frame further comprises a targetreceive power for the plurality of UL sounding signals.

In Example 58, the subject matter of any one or more of Examples 54-57optionally include where the instructions further configure the one ormore processors to cause the apparatus to: select a second plurality ofsecond wireless devices of the plurality of second wireless devices witha receive signal strength of the plurality of UL sounding signals abovea threshold for an additional trigger frame; encode the additionaltrigger frame including second RU allocations, and second SS allocationsfor the second plurality of second wireless devices to transmit a secondplurality of UL sounding signals, and including an indication that theadditional trigger frame is for the second plurality of UL soundingsignals, and where the additional trigger frame comprises a secondtarget receive power greater than the target receive power; configurethe first wireless device to transmit the additional trigger frame tothe second plurality of second wireless devices; and decode the secondplurality of UL sounding signals from the plurality of second wirelessdevices.

Example 59 is a method performed by an apparatus of a first wirelessdevice to: encode a trigger frame including resource unit (RU)allocations, and spatial stream (SS) allocations for a plurality ofsecond wireless devices to transmit a plurality of uplink (UL) soundingsignals, and including an indication that the trigger frame is for theplurality of UL sounding signals; configure the first wireless device totransmit the trigger frame to the plurality of second wireless devices;and decode the plurality of UL sounding signals from the plurality ofsecond wireless devices.

In Example 60, the subject matter of Example 59 optionally includeswhere the trigger frame further comprises an indication of a delay foreach of the plurality of second wireless devices to transmit the ULsounding signals, and where the delay is a same first delay for a firstone or more of the plurality of second wireless devices and a samesecond delay for a second one or more of the plurality of secondwireless devices.

In Example 61, the subject matter of any one or more of Examples 59-60optionally include where the trigger frame comprises a cascade fieldthat indicates an additional trigger frame is to be transmitted andwhere the method further comprises: encoding the additional triggerframe including second RU allocations, and second spatial stream (SS)allocations for a plurality of third wireless devices to transmit asecond plurality of UL sounding signals, and including a secondindication that the additional trigger frame is for the second pluralityof UL sounding signals; configuring the first wireless device totransmit the additional trigger frame to the plurality of third wirelessdevices; and decoding the second plurality of UL sounding signals fromthe plurality of third wireless devices.

In Example 62, the subject matter of any one or more of Examples 59-61optionally include where the trigger frame further comprises a targetreceive power for the plurality of UL sounding signals.

In Example 63, the subject matter of any one or more of Examples 59-62optionally include where the method further comprises: selecting asecond plurality of second wireless devices of the plurality of secondwireless devices with a receive signal strength of the plurality of ULsounding signals above a threshold for an additional trigger frame;encoding the additional trigger frame including second RU allocations,and second SS allocations for the second plurality of second wirelessdevices to transmit a second plurality of UL sounding signals, andincluding an indication that the additional trigger frame is for thesecond plurality of UL sounding signals, and where the additionaltrigger frame comprises a second target receive power greater than thetarget receive power; configuring the first wireless device to transmitthe additional trigger frame to the second plurality of second wirelessdevices; and decoding the second plurality of UL sounding signals fromthe plurality of second wireless devices.

Example 64 is an apparatus of a first wireless device, the apparatusincluding: means for encoding a trigger frame including resource unit(RU) allocations, and spatial stream (SS) allocations for a plurality ofsecond wireless devices to transmit a plurality of uplink (UL) soundingsignals, and including an indication that the trigger frame is for theplurality of UL sounding signals; means for configuring the firstwireless device to transmit the trigger frame to the plurality of secondwireless devices; and means for decoding the plurality of UL soundingsignals from the plurality of second wireless devices.

In Example 65, the subject matter of Example 64 optionally includeswhere the trigger frame further comprises an indication of a delay foreach of the plurality of second wireless devices to transmit the ULsounding signals, and where the delay is a same first delay for a firstone or more of the plurality of second wireless devices and a samesecond delay for a second one or more of the plurality of secondwireless devices.

In Example 66, the subject matter of any one or more of Examples 64-65optionally include where the trigger frame comprises a cascade fieldthat indicates an additional trigger frame is to be transmitted andwhere the apparatus further comprises: means for encoding the additionaltrigger frame including second RU allocations, and second spatial stream(SS) allocations for a plurality of third wireless devices to transmit asecond plurality of UL sounding signals, and including a secondindication that the additional trigger frame is for the second pluralityof UL sounding signals; means for configuring the first wireless deviceto transmit the additional trigger frame to the plurality of thirdwireless devices; and means for decoding the second plurality of ULsounding signals from the plurality of third wireless devices.

In Example 67, the subject matter of any one or more of Examples 64-66optionally include where the trigger frame further comprises a targetreceive power for the plurality of UL sounding signals.

In Example 68, the subject matter of any one or more of Examples 64-67optionally include where the apparatus further comprises: means forselecting a second plurality of second wireless devices of the pluralityof second wireless devices with a receive signal strength of theplurality of UL sounding signals above a threshold for an additionaltrigger frame; means for encoding the additional trigger frame includingsecond RU allocations, and second SS allocations for the secondplurality of second wireless devices to transmit a second plurality ofUL sounding signals, and including an indication that the additionaltrigger frame is for the second plurality of UL sounding signals, andwhere the additional trigger frame comprises a second target receivepower greater than the target receive power; means for configuring thefirst wireless device to transmit the additional trigger frame to thesecond plurality of second wireless devices; and means for decoding thesecond plurality of UL sounding signals from the plurality of secondwireless devices.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. An apparatus of a first wireless device, theapparatus+: memory; and processing circuitry coupled to the memory, theprocessing circuitry configured to: decode a trigger frame comprising aresource unit (RU) allocation, and a spatial stream (SS) allocation forthe first wireless device to transmit an uplink (UL) sounding signal,and wherein the trigger frame comprises an indication that the triggerframe is for the UL sounding signal and an indication of a transmitpower used by a second wireless device to transmit the trigger frame;determine a path loss based on the indication of the transmit power anda received power of the trigger frame at the first wireless device;determine a transmit power for the UL sounding signal based on the pathloss; and configure the first wireless device to transmit the ULsounding signal in accordance with the RU allocation, the SS allocation,and the transmit power.
 2. The apparatus of claim 1, wherein the triggerframe further comprises a target receive power for the UL soundingsignal, and wherein the processing circuitry is further configured to:determine the transmit power for transmission of the UL sounding signalbased on the path loss so that the UL sounding signal will be receivedby the second wireless device with the target receive power.
 3. Theapparatus of claim 2, wherein processing circuitry is further configuredto: normalize the target receive power in accordance with a bandwidth ofthe RU allocation, wherein the target receive power is a target receivepower density.
 4. The apparatus of claim 1, wherein the processingcircuitry is further configured to: determine the transmit power to be apower below a limit but large enough for a highest modulation and codingscheme (MCS) the first wireless device is able to use to encode a packetto transmit to communicate with the second wireless device within areliability parameter.
 5. The apparatus of claim 4, wherein the limit isa regulatory transmission limit for the RU allocation, a co-locationtransmission limit, or a power amplifier limit.
 6. The apparatus ofclaim 4, wherein the processing circuitry is further configured to:determine the highest MCS the first wireless device is able to use basedon an estimated error vector magnitude (EVM) of a packet to be receivedat the second wireless device, wherein the packet is to be encoded withthe highest MCS.
 7. The apparatus of claim 1, wherein the trigger framecomprises a carrier sense field to indicate if the first wireless deviceis to perform a clear channel analysis (CCA) before transmitting the ULsounding signal, and wherein the processing circuitry is configured to:if the carrier sense field indicates that a CCA is to be performedbefore transmitting the UL sounding signal, perform a clear channelanalysis (CCA) on the RU allocation, and if the CCA indicates the RUallocation is idle, configure the first wireless device to transmit theUL sounding signal in accordance with the RU allocation, the SSallocation, and the transmit power.
 8. The apparatus of claim 1, whereinthe UL sounding signal is a null data packet (NDP).
 9. The apparatus ofclaim 1, wherein the trigger frame indicates that the trigger frame isfor the UL sounding signal based on a length or duration field of thetrigger frame that indicates there is no length or duration for data, orbased on a trigger frame type field.
 10. The apparatus of claim 1,wherein the trigger frame indicates the UL sounding signal is to be onefrom the following group: an high efficiency (HE) preamble symbolduration of 3.2 μs (1× long-training field (LTF)), a HE preamble symbolduration of 6.4 μs (2×LTF), a HE preamble symbol duration of 12.8 μs(4×LTF), a legacy NDP, an Institute of Electrical and ElectronicEngineers (IEEE) 802.11ac NDP format, or an IEEE 802.11n NDP.
 11. Theapparatus of claim 1, wherein the trigger frame further comprises adelay time that indicates how long the first wireless device is to waitbefore transmitting the UL sounding signal in accordance with the RUallocation and the SS allocation.
 12. The apparatus of claim 11, whereinone or more additional wireless devices are to transmit UL soundingsignals before the delay time.
 13. The apparatus of claim 1, wherein theprocessing circuitry is further configured to: determine a transmitpower to transmit the UL sounding signal based on the path loss andfurther based on a bandwidth of the RU allocation.
 14. The apparatus ofclaim 1, wherein the trigger frame indicates that no acknowledgment ofthe UL sounding signal is to be transmitted by the second wirelessdevice.
 15. The apparatus of claim 1, wherein the processing circuitryis further configured to: configure the first wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power, and in accordance with one orboth of orthogonal frequency division multi-access (OFDMA) or multi-usermultiple-input multi-output (MU-MIMO).
 16. The apparatus of claim 1,wherein the first wireless device is one from the following group: anInstitute of Electrical and Electronic Engineers (IEEE) 802.11ax accesspoint, an IEEE 802.11ax station, an IEEE 802.11 station, and an IEEE802.11 access point.
 17. The apparatus of claim 1, further comprisingtransceiver circuitry coupled to the processing circuitry.
 18. Theapparatus of claim 17, further comprising one or more antennas coupledto the transceiver circuitry.
 19. A non-transitory computer-readablestorage medium that stores instructions for execution by one or moreprocessors, the instructions to configure the one or more processors tocause an apparatus of a first wireless device to: decode a trigger framecomprising a resource unit (RU) allocation, and a spatial stream (SS)allocation for the first wireless device to transmit an uplink (UL)sounding signal, and wherein the trigger frame comprises an indicationthat the trigger frame is for the UL sounding signal and an indicationof a transmit power used by a second wireless device to transmit thetrigger frame; determine a path loss based on the indication of thetransmit power and a received power of the trigger frame at the firstwireless device; determine a transmit power for the UL sounding signalbased on the path loss; and configure the first wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power.
 20. The non-transitorycomputer-readable storage medium of claim 19, wherein the instructionsfurther configure the one or more processors to cause the apparatus to:determine the transmit power for transmission of the UL sounding signalbased on the path loss so that the UL sounding signal will be receivedby the second wireless device with a target receive power, wherein thetrigger frame further comprises the target receive power for the ULsounding signal.
 21. A method performed by an apparatus of a firstwireless device, the method comprising: decode a trigger framecomprising a resource unit (RU) allocation, and a spatial stream (SS)allocation for the first wireless device to transmit an uplink (UL)sounding signal, and wherein the trigger frame comprises an indicationthat the trigger frame is for the UL sounding signal and an indicationof a transmit power used by a second wireless device to transmit thetrigger frame; determine a path loss based on the indication of thetransmit power and a received power of the trigger frame at the firstwireless device; determine a transmit power for the UL sounding signalbased on the path loss; and configure the first wireless device totransmit the UL sounding signal in accordance with the RU allocation,the SS allocation, and the transmit power.
 22. The method of claim 21,wherein the trigger frame further comprises a target receive power forthe UL sounding signal, and wherein the method further comprises:determining the transmit power for transmission of the UL soundingsignal based on the path loss so that the UL sounding signal will bereceived by the second wireless device with the target receive power.23. An apparatus of a wireless device, the apparatus comprising: memory;and processing circuitry coupled to the memory, the processing circuitryconfigured to: decode a trigger frame comprising a resource unit (RU)allocation, and a spatial stream (SS) allocation for the wireless deviceto transmit an uplink (UL) sounding signal, and wherein the triggerframe comprises an indication that the trigger frame is for the ULsounding signal; determine a transmit power to transmit the UL soundingsignal based on a highest power the first wireless can use for the RUallocation; and configure the wireless device to transmit the ULsounding signal in accordance with the RU allocation, the SS allocation,and the transmit power.
 24. The apparatus of claim 23, wherein thehighest power is based on one of the following group: a regulatoryhighest power for the RU allocation and a co-located wirelesscommunication protocol highest power.
 25. An apparatus of a firstwireless device, the apparatus comprising: memory; and processingcircuitry coupled to the memory, the processing circuitry configured to:encode a trigger frame comprising resource unit (RU) allocations, andspatial stream (SS) allocations for a plurality of second wirelessdevices to transmit a plurality of uplink (UL) sounding signals, andcomprising an indication that the trigger frame is for the plurality ofUL sounding signals; configure the first wireless device to transmit thetrigger frame to the plurality of second wireless devices; and decodethe plurality of UL sounding signals from the plurality of secondwireless devices.
 26. The apparatus of claim 25, wherein the triggerframe further comprises an indication of a delay for each of theplurality of second wireless devices to transmit the UL soundingsignals, and wherein the delay is a same first delay for a first one ormore of the plurality of second wireless devices and a same second delayfor a second one or more of the plurality of second wireless devices.27. The apparatus of claim 25, wherein the trigger frame comprises acascade field that indicates an additional trigger frame is to betransmitted and wherein the processing circuitry is further configuredto: encode the additional trigger frame comprising second RUallocations, and second spatial stream (SS) allocations for a pluralityof third wireless devices to transmit a second plurality of UL soundingsignals, and comprising a second indication that the additional triggerframe is for the second plurality of UL sounding signals; configure thefirst wireless device to transmit the additional trigger frame to theplurality of third wireless devices; and decode the second plurality ofUL sounding signals from the plurality of third wireless devices. 28.The apparatus of claim 25, wherein the trigger frame further comprises atarget receive power for the plurality of UL sounding signals.
 29. Theapparatus of claim 28, wherein the processing circuitry is furtherconfigured to: select a second plurality of second wireless devices ofthe plurality of second wireless devices with a receive signal strengthof the plurality of UL sounding signals above a threshold for anadditional trigger frame; encode the additional trigger frame comprisingsecond RU allocations, and second SS allocations for the secondplurality of second wireless devices to transmit a second plurality ofUL sounding signals, and comprising an indication that the additionaltrigger frame is for the second plurality of UL sounding signals, andwherein the additional trigger frame comprises a second target receivepower greater than the target receive power; configure the firstwireless device to transmit the additional trigger frame to the secondplurality of second wireless devices; and decode the second plurality ofUL sounding signals from the plurality of second wireless devices.